US fastfood giant McDonald's has launched a soy-based meatless burger in 600 outlets in Southern California.

The new McVeggie Burger is being manufactured by Yves Veggie Cuisine, a brand owned by Hain Celestial Group, and will form part of McDonald's new "Salads & More" menu. The burgers are to be manufactured at the Yves Veggie Cuisine plant in Vancouver.

The vegetarian burger has 8g of fat and 350 calories, compared with a Big Mac's 34g of fat and 350 calories. Hain Celestial said the burger is also cholesterol free and low in saturated fat.

It is not yet clear whether McDonald's plans to go national with the McVeggie Burger.

Although McDonald's and Burger King both offer vegetarian burgers in a handful of other countries, including the UK, the products have only recently been made available in the US.

McDonald's rival Burger King launched the BK Veggie Burger last year after testing the product in Canada, reported Dow Jones News Service.